GitHub Actions で npm パッケージを公開する（アルファ版向け簡易フロー）

{
  "repository": {
    "type": "git",
    "url": "https://github.com/your-org/your-repo.git",
    "directory": "packages/core"
  }
}

name: Publish npm package

on:
  workflow_dispatch:
    inputs:
      package:
        description: '公開するパッケージを選択'
        required: true
        type: choice
        options:
          - '@example/core'
          - '@example/utils'
          - '@example/cli'
      version_type:
        description: 'バージョンの上げ方'
        required: true
        type: choice
        default: 'prerelease'
        options:
          - prerelease # 0.1.0-alpha.1 → 0.1.0-alpha.2
          - prepatch # 0.1.0-alpha.1 → 0.1.1-alpha.0
          - preminor # 0.1.0-alpha.1 → 0.2.0-alpha.0
          - premajor # 0.1.0-alpha.1 → 1.0.0-alpha.0

jobs:
  publish:
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main' # main ブランチからのみ実行可能
    permissions:
      contents: write
      id-token: write # OIDC Trusted Publishing に必要
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Setup pnpm
        uses: pnpm/action-setup@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '24'
          cache: 'pnpm'
          registry-url: 'https://registry.npmjs.org'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Configure git
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

      - name: Get package directory
        id: package-dir
        run: |
          # パッケージ名からディレクトリを取得
          # 実際のプロジェクト構成に合わせて変更してください
          case "${{ inputs.package }}" in
            "@example/core")
              echo "dir=packages/core" >> $GITHUB_OUTPUT
              ;;
            "@example/utils")
              echo "dir=packages/utils" >> $GITHUB_OUTPUT
              ;;
            "@example/cli")
              echo "dir=packages/cli" >> $GITHUB_OUTPUT
              ;;
          esac

      - name: Build package
        run: pnpm turbo build --filter="${{ inputs.package }}"

      - name: Bump version
        id: version
        working-directory: ${{ steps.package-dir.outputs.dir }}
        run: |
          npm version ${{ inputs.version_type }} --preid=alpha --no-git-tag-version
          NEW_VERSION=$(node -p "require('./package.json').version")
          echo "new_version=$NEW_VERSION" >> $GITHUB_OUTPUT

      - name: Commit version bump
        run: |
          git add .
          git commit -m "release(${{ inputs.package }}): ${{ steps.version.outputs.new_version }}"
          git push

      - name: Create git tag
        id: tag
        run: |
          TAG_NAME="${{ inputs.package }}@${{ steps.version.outputs.new_version }}"
          git tag "$TAG_NAME"
          git push origin "$TAG_NAME"
          echo "tag_name=$TAG_NAME" >> $GITHUB_OUTPUT

      - name: Create GitHub Release
        run: gh release create "${{ steps.tag.outputs.tag_name }}" --title "${{ steps.tag.outputs.tag_name }}" --generate-notes --prerelease
        env:
          GH_TOKEN: ${{ github.token }}

      # Trusted Publishing: pnpm pack + npm publish
      # pnpm pack で workspace:* を実際のバージョンに解決した tarball を作成
      - name: Publish to npm (Trusted Publishing)
        working-directory: ${{ steps.package-dir.outputs.dir }}
        run: |
          pnpm pack
          npm publish *.tgz --access=public --tag alpha --provenance

      - name: Summary
        run: |
          echo "## Published successfully! :rocket:" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "- **Package:** ${{ inputs.package }}" >> $GITHUB_STEP_SUMMARY
          echo "- **Version:** ${{ steps.version.outputs.new_version }}" >> $GITHUB_STEP_SUMMARY
          echo "- **Tag:** alpha" >> $GITHUB_STEP_SUMMARY
          echo "- **Auth:** Trusted Publishing (OIDC)" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "[View on npm](https://www.npmjs.com/package/${{ inputs.package }})" >> $GITHUB_STEP_SUMMARY